Problem:
Fuel pump seeps oil out of small port on fuel pump. Mower would not run.
What I tried:
I replaced the fuel pump...same results.
I bypassed the fuel pump and ran the gas line straight to the carb. This worked...but only till the fuel level gets below the carb level.
I am assuming that the pump is some sort of diaphram type that somehow pumps due to the connection to the crankcase...but have no idea how to test and troubleshoot further so I though I would ask you guys.
I am assuming that this is an OHV engine. Here is a test I would like you to perform, before spending any more money. Start the unit with gravity feed and run it at 3/4 throttle. Slowing and carefully remove the oil fill cap and let it rest on the fill tube. If it starts bouncing all over, and you see a mist of oil existing the tube, your problem is probably a blown head gasket. What is occurring is that with the bad gasket, too much pressure is building in the crankcase, causing oil instead of air to be pushed through the fuel pump pulse line.
Rivets,
I did the test and indeed the filler cap did bounce a lot. I did pull it all the way out and it did spew out oil droplets. I will replace the head gasket and see if that remedies the problem. Thanks for your input and time. I will respond with the results but may be a few days before I can get to it. Again thanks.
